A photoelectric conversion module includes a photoelectric conversion element that converts an arriving optical signal transmitted via an optical fiber into an electrical signal, a signal output section that outputs a photoelectrically converted electrical signal to the exterior, an impedance matching circuit provided between an output electrode of the photoelectric conversion element and the signal output section, and a substrate upon which this impedance matching circuit is mounted, with the impedance matching circuit including a plurality of metallic coating layers formed upon the surface of the substrate with gaps being left between them, and a plurality of metallic connecting lines that electrically connect together adjacent ones of these metallic coating layers.